A NOVEL ANALOGUE BIO-IMPEDANCE SYSTEM-ON-A-CHIP FOR MONITORING OF NEONATE LUNG FUNCTION

本研究提出了一种迫切需要的电阻抗断层扫描（EIT）为基础的生物成像系统在重症监护病房（ITUs）的新生儿肺功能的体内监测的发展。肺生长、成熟和呼吸控制障碍是肺科医生面临的最重要的问题之一。早产发生在所有怀孕的5-10%，并经常伴随着由于肺不成熟的并发症。NHS每年的费用估计在数亿美元左右。新生儿ITU肺功能监测的关键困难之一是系统必须以被动方式测量受试者，而不像成年人可以被要求执行特定的呼吸任务。EIT是解决这个问题的唯一方法。此外，EIT在许多临床应用中也证明是成功的，例如用于检测乳腺癌的新商业TSCAN系统，拟议的系统将提供一种非侵入性的测量肺成熟度和发育，氧气需求和肺功能，适用于未使用镇静剂的小婴儿。该工具将常规用于定义持续性肺部疾病的性质和严重程度，并确定发生慢性肺部问题的风险因素。EIT的主要局限性是固有的共模误差，这会导致重建图像质量的降低。这些误差在多频率EIT的情况下更明显。我们已经发明了一种方法来解决这个问题，通过使用一种新的宽带模拟共模增强技术，可以最大限度地提高整体共模抑制比（CMRR）和信噪比（SNR）。为了充分利用我们的宽带CMRR反馈方法的能力，我们将使用全定制电路设计技术来创建一个新颖的多频EIT系统的硅芯片。我们还开发了先进的重建方法，涉及新的网格扭曲技术，利用边界信息的条件下的正向模型，考虑到解剖细节的问题域。这项研究的最终结果将是一种可穿戴设备形式的新技术，它将在监测新生儿时最大限度地减少干扰。这将涉及定制硅芯片的设计，集成的可穿戴电极系统，新的3D图像重建算法和先进的后图像处理方法。这项研究将在位于伦敦大奥蒙德街的世界领先儿童医院的Portex麻醉、强化治疗和呼吸内科的全面临床支持下进行。

This research proposes the development of an urgently needed Electrical Impedance Tomography (EIT)-based bio-imaging system for in-vivo monitoring of neonate lung function in Intensive care Units (ITUs). Disorders of lung growth, maturation and breathing control are among the most important problems faced by the neonatologist. Premature birth occurs in 5-10% of all pregnancies, and is frequently accompanied by complications due to lung immaturity. The annual cost to the NHS is estimated in the order of hundreds of millions. One of the key difficulties of neonate ITU monitoring for lung function is that the system must measure the subject in a passive manner, unlike adults who can be asked to perform specific respiratory tasks. EIT is the only solution to this problem. Moreover, EIT is proving to be successful in many clinical applications, an example is the new commercial TSCAN system for detection of breast cancer.The proposed system will provide a non-invasive measure of lung maturity and development, oxygen requirements and lung function, suitable for use in small, unsedated infants. This tool will be routinely used to define the nature and severity of persisting lung disease, and to identify risk factors for developing chronic lung problems. Major limitations of EIT are the inherent common mode errors which result in reduction of the quality of the reconstructed images. These errors are more pronounced in the case of multi-frequency EIT. We have invented a method to address the problem by the use of a novel wideband analogue common-mode enhancement technique which can maximise the overall common-mode rejection ratio (CMRR) and signal-to-noise ratio (SNR). To take full advantage of the capabilities of our wideband CMRR feedback approach, we will use full custom circuit design techniques to create a novel multi-frequency EIT system-on-a-silicon-chip. We have also developed advanced reconstruction methods involving new mesh warping techniques that utilise the boundary information to condition the forward model, taking into account the anatomical details of the problem domain. The end result of this research will be new technology in the form of a wearable device which will minimise disruption when monitoring neonates. This will involve the design of custom made silicon chips, an integrated wearable electrode system, new 3D image reconstruction algorithms and advanced post image processing methodologies. This research will be carried out with the full clinical support of the Portex Anaesthesia, Intensive Therapy and Respiratory Medicine Unit at the world leading children's Hospital, Great Ormond Street, London.